9th floor
You can. But pay attention to a number of nuances:
Video recording by surveillance cameras can be carried out only within the boundaries of one's apartment, house or yard;
Install a sign with the inscription that a security system is installed in private properties, and events are recorded by surveillance cameras. Thus, passers-by are warned that their images may be captured by cameras and stored in memory devices.
Understand that any person whose image has entered the storage of the video surveillance system has the right to request the footage or offer to destroy the video information, and the owner is obliged to fulfill his wish. Exceptions are requests by criminals and cases where an incident is being investigated, of which the requester must be notified.
Take into account that it is mandatory to respond to any oral or written requests for viewing the filmed material or deleting existing data within one month from the moment of the request.